Extraluminal balloon dissection

ABSTRACT

The present invention provides balloon dissection apparatus and methods of use in which an elongate balloon is utilized to dissect along a region that follows a naturally existing path alongside a vessel or structure, such as an artery, a vein, a lymphatic, the trachea, the esophagus or even a nerve bundle.

This application is a continuation of U.S. application Ser. No.10/238,108, filed Sep. 9, 2002 now U.S. Pat. No. 6,764,497, which is acontinuation of U.S. application Ser. No. 09/873,930, filed on Jun. 4,2001, now U.S. Pat. No. 6,447,529, which is a continuation of U.S.application Ser. No. 09/039,548, filed on Mar. 16, 1998, now U.S. Pat.No. 6,013,090, which is a continuation of U.S. application Ser. No.08/824,676, filed on Mar. 26, 1997, now U.S. Pat. No. 5,814,060, whichis a continuation of U.S. application Ser. No. 08/631,221, filed on Apr.11, 1996, now U.S. Pat. No. 5,690,668, which is a continuation-in-partof U.S. application Ser. No. 08/267,484, filed on Jun. 29, 1994, nowU.S. Pat. No. 5,601,589, the disclosures of which are herebyincorporated by reference in their entirety.

FIELD OF THE INVENTION

The present invention relates generally to the field of extraluminalballoon dissection. More particularly, the present invention relates tovascular methods and apparatus which can used for creating an anatomicworking space alongside an elongate structure, such as a vessel ornerve, for example.

BACKGROUND OF THE INVENTION

In commonly assigned copending application Ser. No. 07/893,988, filed onJun. 2, 1992, apparatus and methods are disclosed for developing ananatomic working space for laparoscopic procedures using balloondissection. In commonly assigned copending application Ser. No.08/570,766, filed on Dec. 12, 1995, further improvements to theapparatus and methods disclosed in application Ser. No. 07/893,988 aredisclosed. The disclosure of each of these prior applications is herebyincorporated by reference in its entirety. The apparatus and methodsdisclosed in the referenced prior applications include balloondissection apparatus with relatively large surface balloons which expandlaterally and are not particularly well suited for surgical procedure onelongate structures. There is therefore a need for new and improvedballoon dissection apparatus and associated methods of use fordissecting or creating space alongside elongate structures in the body.

SUMMARY OF THE INVENTION

The present invention provides balloon dissection apparatus and methodsof use in which an elongate balloon is utilized to dissect along aregion that follows a naturally existing path alongside a vessel orstructure, such as an artery, a vein, a lymphatic vessel, the trachea,the esophagus, or even a nerve bundle.

The balloon dissection apparatus for use in extraluminal balloondissection as described herein may utilize an elongate balloon with atunneling shaft assembly of the types described in any one of copendingU.S. application Ser. Nos. 07/893,988, 08/124,283, 08/267,488,08/388,233, 08/403,012, or 08/570,766, the disclosure of each of whichis hereby incorporated by reference in its entirety. U.S. Pat. No.4,271,839 to Fogarty et al. which discloses a balloon catheter with oninverted balloon is also expressly incorporated by reference herein.

In a preferred embodiment, the deflated elongate balloon has at least apart of its distal extremity folded inwardly to shorten itspredeployment length. The distal portion of the elongate balloon may beinverted into the proximal portion and folded inwardly to provide aballoon having a folded length of roughly one-half the length of thefully distended balloon. Additional inward folds may be provided tofurther shorten the balloon.

In another preferred embodiment, a thumb-shaped balloon reservoir may beprovided as an integral portion of the elongate balloon. The balloonreservoir generally remains outside the body and serves to store thedistal portion of the inverted, folded balloon prior to deployment Bystoring the bulk of the deflated balloon outside of the body in thereservoir a longer balloon can be utilized. Provision is made forlaparoscopic observation.

A bi-directionally expanding balloon is also disclosed which is usefulwhen anatomical obstructions would cause a balloon expanding in onedirection only to be blocked. The bi-directional balloon may be utilizedeither with or without the aid of laparoscopic observation.

In a preferred method of performing extraluminal balloon dissection, adeflated and folded elongate balloon is inserted into an incision in thebody adjacent the elongate structure aided by a laparoscope, a finger,or other tunneling member. The folded elongate balloon is thenoptionally bluntly advanced alongside the elongate structure until aregion where it is desired to perform balloon dissection is reached Asthe balloon is advanced alongside the elongate structure a laparoscopemay be utilized to observe beyond the distal end of the balloon, eitherfrom within or alongside the balloon. An inflation medium is thenintroduced into the balloon to cause the balloon to event and propagatedistally alongside the elongate structure to dissect the structure alonga natal tissue plane. The laparoscope may also be use to observedissection as the balloon propagates alongside the structure ifprovided. After the structure has been dissected the balloon may bedeflated and withdrawn through the incision. The anatomic operatingspace alongside the vessel created by the dissecting balloon may then beinsufflated and a surgical procedure performed.

BRIEF DESCRIPTION OF THE DRAWINGS

Reference is made to the accompanying drawings, where like referencenumerals are used on like parts and where illustrative embodiments ofthe invention are shown from which one of ordinary skill in the art willappreciate novel features and advantages of the present invention.

In the drawings:

FIG. 1 is a side elevational view of an extraluminal balloon dissectionapparatus incorporating aspects of the present invention.

FIG. 2 is a cross-sectional view taken along line 2—2 in FIG 1.

FIG. 3 is a view of the human leg illustrating the present inventionbeing used to create an atomic working space alongside a saphenous veinduring a saphenous vein bypass procedure.

FIG. 4 is a cross sectional view taken along line 4—4 in FIG. 3.

FIG. 5 is a side elevational view of another embodiment of anextraluminal balloon dissection apparatus according to the presentinvention.

FIG. 6 is a cross sectional view taken along lines 6—6 in FIG. 5.

FIG. 7 is a side elevational view of yet another embodiment of anapparatus according to the present invention.

FIG. 8 is a cross sectional view taken along line 8—8 in FIG. 7.

FIG. 9 is a cross sectional view showing the balloon of FIG. 8 after ithas been inflated.

FIG. 10 is a plan view of another embodiment of an extraluminal balloondissection apparatus according to the invention illustrating the foldingand storage of the elongate balloon within a thumb-shaped balloonreservoir.

FIG. 11 is a plan view of the apparatus of FIG. 10 showing the elongateballoon fully distended after inflation.

FIG. 12 is plan view of another embodiment of an extraluminal balloondissection apparatus according to the invention utilizing an elongateballoon and a thumb-shaped balloon reservoir.

FIG. 13 is a plan view of the apparatus of FIG. 12 showing the elongateballoon fully distended after inflation.

FIG. 14 is a plan view of another embodiment of an extraluminal balloondissection apparatus according to the invention utilizing a balloonreservoir and a bulb-shaped balloon.

FIG. 15 is a plan view of yet another embodiment of an extraluminalballoon dissection apparatus according to the invention utilizing aballoon reservoir and a bulb shaped balloon.

FIG. 16 is a side elevational view of another embodiment of anextraluminal balloon dissection apparatus according to the inventionhaving two balloon reservoirs and a bi-directionally expanding elongateballoon.

FIG. 17 is a side elevational view of the FIG. 16 embodimentillustrating the apparatus after the bi-directionally expanding balloonhas been inflated and is fully distended.

FIG. 18 is a side elevational view of another embodiment of anextraluminal balloon dissection apparatus according to the inventionwhich is substantially similar to the embodiment of FIG. 16 whichprovides for laparoscopic observation.

FIG. 19 is a side elevational view of the FIG. 18 embodiment after thebi-directionally expanding balloon has been inflated and is fullydistended.

FIG. 20 is a plan view of a balloon reinforcing sleeve which may beutilized with an extraluminal balloon dissection apparatus in accordancewith the invention.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

In the exemplary embodiment illustrated in FIG. 1, an extraluminalballoon dissection apparatus 11 includes a tunneling shaft assembly 30substantially similar to the tunneling shaft assembly disclosed inapplication Ser. No. 07/893,988, an elongate balloon 32, a skin seal 21,and a removable balloon cover 51. The tunneling shaft assembly 30 has athree-piece handle 13, Alternatively, a hollow tube having either a oneor two piece handle construction as disclosed in Ser. No. 08/570,766 maybe utilized with an elongate balloon according to the invention. Thethree-piece handle 13 includes a cannula 18, an obturator 15, and atunneling shaft 16, each of which extend from a different section of thehandle 13. The tunneling shaft 16 extends through a bore in theobturator 15, and the obturator 15 extends through the cannula 18. Thetunneling shaft 16 may have an olive-shaped, or other blunt shapedobjector 17 mounted on its distal end to provide a blunt distal end fortunneling. A skin seal 21 substantially as described in Ser. No.08/124,283 may be utilized if needed for the procedure to be performed,in which case, the skin seal 21 is slidably mounted and fictionallyretained on the outer surface of the cannula 18. A moveable collar 26 onthe skin seal 21 provides for adjustment on and locking to the outersurface of the cannula 18. The outer surface 22 of the skin seal 21 isprogressively cylindrical and tapered and provided with helical screwthreads 23 for engaging the skin of the patient to form a sealtherewith.

As shown in FIGS. 1 and 2, an elongate balloon 32 is mounted on thetunneling shaft 16 which is part of the tunneling assembly 30. Theelongate balloon 32, which may be described as having a hot dog shape,is generally cylindrical and has a distal end 34 which extendssubstantially beyond the distal most point of the tunneling shaft 16when fully inflated, as shown by the dashed extension lines in FIG. 1.The elongate balloon 32 is preferably formed from a nonelastic materialso that its expansion envelope can be fairly well regulated as is knownto those of skill in the art. The balloon cover 51, which may be formedintegrally with the balloon 32 as disclosed in copending applicationSer. No. 08/570,766, for example, or as a separable component asillustrated in FIG. 1, encloses the deflated balloon 32 and holds itagainst the tunneling shaft 16.

Prior to use, the distal portion 34 of the deflated balloon 32 is foldedinwardly to shorten its length so that the distal portion 34 of thefolded balloon 32 does not extend substantially beyond the distalextremity of the tunneling shaft 16. The distal portion 34 of theballoon 32 can be folded inwardly by inverting the distal portion 34 ofthe balloon 32 into the proximal portion 35 so that approximatelyone-half of the length of the balloon 32 is folded into the other halfof the balloon 32. This reduces the overall length of the deflatedballoon 32 to approximately one half of its fully extended length. If ashorter folded balloon 32 is necessary for the particular procedurecontemplated, it is possible to flier shorten the balloon 32 by againfolding the distal most portion of the balloon 32 inwardly so that thedeflated balloon 32 is now only approximately one-fourth of its fullyextended length.

In the embodiment shown in FIGS. 1 through 4, the balloon 32 isreleasably secured to the tunneling shaft 16 by a sleeve 36, as bestshown in FIG. 2. The sleeve 36 call be formed from the same material asthe balloon 32 and may be formed as an integral part of the balloon 32by bonding the balloon material together as shown at reference numeral37 in FIG. 2. Alternatively, the sleeve 36 may be formed as a separatemember of the balloon 32 and bonded to the balloon 32 by welding, heatsealing, or through the use of a suitable adhesive, for example. Thesleeve 36 extends substantially along the entire length of the balloon32 and circumscribes the tunneling shaft 16. The sleeve 36 is preferablyprovided with a weakened region 37 extending the length thereof whichcan be formed in a suitable manner, such as by providing axialperforations extending along the length of the sleeve 36. The weakenedregion 37 permits the sleeve 36 to be separated from the tunneling shaft16 when it is desired to separate the balloon 32 from the tunnelingshaft 16, as will be described below.

In order to inflate the balloon 32, a flexible tubular member 41 may beutilized as an inflation lumen for the balloon 32. The distal extremityof the tubular member 41 is inserted into the balloon 32 so that thelumen in the tubular member 41 opens into the interior space of theballoon 32. A wye adaptor 42 is secured to the proximal extremity of thetubular member 41. A hand operated syringe 43 may be connected to thewye adaptor 42 as shown in FIG. 1 and utilized to inflate the balloon 32with a suitable fluid, such as saline solution, for example. The wyeadaptor 42 is also connected to another fitting 44 by tube 46 which hasa pinch clamp 47 mounted thereon. A male evacuation fitting 44terminates the tube 46 and may be connected to wall suction to evacuatethe balloon 32 after the balloon 32 has been deployed to dissect as willbe described below.

In FIGS. 1 through 4, a removable balloon cover 51 of the type describedin copending application Ser. Nos. 07/893,988 or 08/124,283 may beutilized in connection with the extraluminal balloon dissectionapparatus 11 disclosed. The removable balloon cover 51 serves tofrictionally retain the collapsed balloon 32 relative to the tunnelingshaft 16. The removable balloon cover 51 preferably has a weakenedregion 52 (see FIG. 2) extending along the length thereof to permit theballoon cover 51 to be separated form the balloon 32 and the tunnelingshaft 16 when it is desired to inflate the balloon 32. An integralballoon cover of the type described in Ser. No. 08/267,488, for example,may be utilized with the balloon dissection apparatus 11 in lieu of theremovable cover 51. Such an integral balloon cover may be provided witha weakened region extending along its length so that the balloon coverseparates from the balloon 32 and the tunneling shaft 16 as the balloon32 is inflated. Alternatively, the balloon 32 can be packed into theballoon cover 51 without a guide shaft 16.

Turning now to FIGS. 3 and 4, operation and use of the extraluminalballoon dissection apparatus 11 will now be described in connection withan exemplary balloon dissection procedure. One example of a procedurewhere the present balloon dissection apparatus 11 may be used issaphenous vein bypass procedure where it is desired to improve thecirculation of arterial blood in the leg 61 of a patient having adiseased artery in the leg 61. As shown in FIG. 3, to perform thisprocedure, an incision 63 is made through the skin 67 in the leg 61immediately adjacent the saphenous vein 64 selected to serve as thebypass. The distal extremity defined by the olive-shaped tip 17 of dieballoon dissection apparatus 11 is then introduced through the incision63 and advanced along the saphenous vein 64 between the vein 64 and theskin 67 until the tunneling shaft 16 and folded balloon 32 are disposedwithin the leg 61 adjacent the saphenous vein 64. It should beappreciated that, if desired, dissection can be accomplished along thesaphenous vein 64 on the side of the vein 64 away from the skin 67.

When the tunneling shaft 16 and folded balloon 32 are in the properposition adjacent the saphenous vein 64, the balloon cover 51 isremoved, either by physically removing the balloon cover 51 (facilitatedby finger ring 31) and withdrawing the cover 51 from the incision or,alternatively, in the case where an integral balloon cover is utilized,by merely inflating the balloon 32 which causes the integral corner toseparate. Once the balloon cover 51 has either been removed (orseparated by inflation of the balloon in the case of an integral cover),the balloon 32 is progressively inflated by introducing a fluid, such assaline solution, for example, through the syringe 43 into the interiorspace of the balloon 32. As the balloon 32 begins to inflate, the distalportion 34 of the balloon 32 begins to unroll, everting outwardly andpropagating in a distal direction downwardly in the leg 61 toward andbeyond the knee 66 until the distal portion 34 of the balloon 32 isfully extended, as shown by the dashed line in FIG. 3. The saphenousvein 64 is dissected from adjacent tissue along its length as theballoon 32 progressively expands and forms a tunnel alongside the vein64. Dissection follows a natural tissue plane immediately adjacent thevessel or elongate structure. The dissecting balloon 32 propagates alongthe vessel following a natural tissue separation plane between thevessel and surrounding tissue. Thus, dissection occurs as the balloon 32progressively inflates and follows the died natural separation planealongside the vessel.

After the balloon 32 has been completely inflated and has extendedalongside the vein 64 causing the vein 64 to be dissected from adjacenttissue, the balloon 32 is deflated by opening the clamp 47 and applyingsuction to fitting 44. After deflation, the balloon 32 may be withdrawnthrough the incision 63 by pulling on the tubular member 41 to cause thereleasable balloon 32 to be separated from the tunneling shaft 16 alongthe weakened region 37 of the sleeve 36. The skin seal 21 is thenoptionally advanced and threaded into the incision 63 to form agas-tight seal with the an 67 if it is desired to insufflate thedissected space alongside the saphenous vein 64. An insufflation gas maybe introduced through the fitting 14 on the handle 13 into the dissectedspace between the saphenous vein 64 and the skin 67 to provide ananatomic working space (68 in FIG. 4) extending lengthwise along thesaphenous vein 64. Th entire tunneling shaft assembly 30 can then beremoved from the incision 63, leaving the skin seal 21 and cannula 18 inplace to maintain a gas-tight seal with the leg 61. The cannula 18 maybe provided with a duckbill or flapper valve (not shown) to prevent thein on gas from escaping through the cannula 18 after withdrawal of thetunneling shaft assembly 30.

The saphenous vein 64 has side branches 69 which are exposed within oradjacent to the insufflated anatomic space 69 extending along saphenousvein 64. Clips (not shown) can be applied to the side branches 69 inseveral ways. For example, an incision can be made at the distalextremity of the insufflated space 68 by the use of a trocar, forexample, and a clip applier can be introduced through the trocar andhemostats or clips can be applied to the side branches 69. In order tofacilitate this aspect of the procedure, a laparoscope may be introducedthrough the skin seal 21 to permit the placement of the clips to beobserved. In this manner, many of the side branches 69 can be clippedutilizing only one incision in the groin another incision below the knee66. Thus, the procedure of the present invention greatly reduces thenumber of incisions required to clip the side branches 69 of thesaphenous vein 64 over traditional open bypass procedures.

Another method of clipping the side branches 69 involves the use of anoperating endoscope which may be introduced through the skin seal 21.The operating endoscope has an instrument chapel though which a clipapplier can be introduced into the dissected space adjacent thesaphenous vein 68 to clip off the side branches 69 while the procedureis being viewed through the endoscope.

If it is desired to advance still further down the leg 68 than can beaccomplished with the first balloon dissection apparatus 11, a secondsimilar balloon dissection apparatus 11 can be introduced through asecond incision lower down the leg and the same procedure utilized todissect the saphenous vein 64 down to the ankle of the patent. The sameprocedure as described above can be utilized to clip off the sidebranches 69 of that portion of the saphenous vein 64 that is dissectedby use of the second apparatus 11. After clipping of the side branches69 has been completed, valves within the saphenous vein 64 can beremoved in a conventional manner if that is desired. To perform thearterial bypass procedure, the upper portion of the saphenous vein 64can then be connected through the first incision to the artery it isdesired to bypass and reconnected through the lower incision. Theincisions may be closed in a conventional manner.

By utilizing a balloon dissection apparatus of the present invention, itis possible to provide working access to the saphenous vein 64 throughonly moderate sized incisions made at the top and bottom of the leg 61and possibly one additional incision in the middle of the leg 61. Thus,use of an extraluminal balloon dissection apparatus eliminates many ofthe incisions in the leg 61 which have previously been required in orderto clip off or occlude the side branches 69 of the saphenous vein 64,The reduced number and length of incisions greatly reduces the risk ofinfections from multiple and large surface area incisions. From apatient standpoint, the pain and recovery time in the hospital aregreatly reduced over traditional procedures.

Balloon dissection apparatus as disclosed herein can also be used forharvesting the saphenous vein for use in a coronary artery bypassprocedure, for example. In the past, it has been necessary to make afull length incision all the way down the leg 61 of the patient toremove the saphenous vein 64 for the bypass procedure. With a balloondissection apparatus of the present invention, it is possible to make asingle incision in the groin in the patient and then utilize the balloondissection apparatus to create an anatomic working space adjacent thesaphenous vein 64 in the leg 61 through balloon dissection. This can beaccomplished by introducing an extraluminal balloon dissection apparatus11 alongside the saphenous vein 64 and thereafter inflating the balloon32 to cause it to evert outwardly and propagate down the leg, in theprocess dissecting tissue away from the saphenous vein 64 alongsubstantially the entire length of the saphenous vein 64 to create ananatomic working space, as previously described. In is procedure theinflation pressures for the balloon 32 are generally below oneatmosphere.

After dissection has occurred, the balloon 32 is removed, and theanatomic working space 68 created by balloon dissection is theninsufflated and additional trocars, as needed, are inserted into theinsufflated dissected space 68. Side branches 69 of the saphenous vein64 may be exposed by additional manual dissection and are clipped andtransected. The saphenous vein 64 is then dissected free from itssurrounding tissue bed and the proximal and distal ends of the vein 64are clipped and transected to allow the saphenous vein 64 to be removedor harvested through the incision 63. This approach drastically reducesthe length of the incision 63 which is normally required to harvest thesaphenous vein 64. The saphenous vein can be pulled out through theincision 63 and the side branches 69 can be closed on the operatingtable in a standard procedure. Similarly, as previously described,valves within the saphenous vein 64 can be removed or disabled in aconventional fashion if need be.

In connection with the present invention, it has been found preferableto utilize a nonelastomeric balloon 32 so that it is possible to controlthe shape of the dissected region. By way of example, for extraluminalprocedures involving the saphenous vein, it is desirable to have atunneling shaft 16 with a length of approximately 12 inches and a fullydistended balloon 32 having a axial length of 20 to 30 inches and amaximum diameter when inflated of approximately 1 to 3 inches. It shouldbe appreciated that different sizes of balloons can be provided inaccordance with the present invention to provide inflated diameters asgreat as 3 to 4 inches where that maybe necessary or desirable.Alternatively, the extraluminal dissection balloons can be of arelatively small diameter, such as 10 millimeters, for example, when itis desired to tunnel down along the natural plane of an artery for thepurpose of inserting a synthetic graft, for example.

In place of a rigid tunneling shaft assembly 30, it should beappreciated that a semi-rigid tunneling assembly could be provided togive some flexibility, yet enough rigidity to make blunt dissectionpossible to facilitate the advancement of the balloon 32 to a desiredlocation alongside the vessel of interest. It should also be appreciatedthat such a balloon dissection apparatus 11 could be utilized inconjunction with other vessels in the human body, as well as with otherelongate structures such as the esophagus, carotid arteries, brain drainshunts, and nerves.

Another embodiment of an extraluminal balloon dissection apparatus 71,according to the invention, is shown in FIGS. 5 and 6. In thisembodiment, the apparatus 71 includes a conventional endoscope 72 whichhas a housing 73, a light inlet fitting 74 mod on the housing 73, and aneye piece 76. The laparoscope 72 has a probe 77 extending from thehousing 73. An objective lens (not shown) mounted in the distalextremity 78 of the probe 77 may provide a suitable viewing angle, suchas a straight viewing angle parallel to the longitudinal axis of theprobe 77 or an angle of 30 degrees with respect to the longitudinalaxis, for example. As is well known to those of the skill in the art,the laparoscope 72 is provided with optics for receiving a light sourceat the fitting 74 and directing the light out the distal extremity 78 ofthe probe 77 so that light is supplied beyond the distal end 78 of theprobe 77. This permits the surgeon to observe beyond the distal end 78of the probe 77 through the eyepiece 76 or on a video monitor, if thelaparoscope utilized is capable of providing a video output.

The balloon dissection apparatus 71 may utilize, as a tunneling member,an elongate tubular member 81. The tubular member 81, in addition toserving as a scope cover for the laparoscope 72, also serves as atunneling member to permit the apparatus 71 to be advanced bluntlyalongside the saphenous vein, following a natural dissection planeadjacent the vein. The tubular member 81 can be of the type described incopending application Ser. No. 08/267,488 and is preferably formed of asuitable transparent material, such as a clear polycarbonate. Thetubular member 81 has a bore extending tberethrough which is sized sothat it can readily accommodate the probe 77 of the laparoscope 72. Thetubular member 81 may have sufficient length to accept the entire lengthof the probe 77. The tubular member 81 has a rounded, substantiallyhemispherical tip 84 at its distal extremity which can be formedintegrally therewith as shown, or alternatively, as a separate piece andbonded to the tubular member 81 by the use of a suitable adhesive, forexample. The tubular member 81 may also have an open, yet blunt, distalextremity as disclosed in copending application Ser. No. 08/570,766, topermit observation through the laparoscope 72 through the open distalend. When a closed, rounded tip 84 is utilized as shown in FIG. 5, thetip 84 is preferably formed from a transparent material, such as a clearpolycarbonate, to facilitate observation through the distal end 84.

To further facilitate observation through a closed distal end, a baffle86 may be mounted in the bore of the tubular member 81 and extendslaterally and axially thereof. The baffle 86 can be formed integrallywith the distal end 84 or, alternatively, can be formed of a separatematerial which is then bonded to the distal and 84 by a suitableadhesive. Assuming that the laparoscope 72 is of a type in which thelight transmitting capabilities are provided in one se region of theprobe 17, and viewing capabilities are provided through the othersemi-circular region, the baffle 86 is positioned in such a manner sothat it will inhibit, if not prevent, light emitted from the distalextremity 78 of the probe from bouncing off the inner surface of thedistal end 84 and creating a glare which may obscure vision through theeye piece 76. In order to prevent such a glare, the baffle 86 ispreferably formed of an opaque material, such as a black opaquematerial, for example. Alternatively, the baffle 86 may be provided withone surface which is opaque so that light cannot be transmitted throughthe baffle 86 to the lower half of the probe 77 making a clear field ofvision possible the tubular member 81.

An elongate balloon 92 similar to the balloon 32 in the previousembodiment may be utilized with the apparatus 71. The balloon 93 hasproximal and distal extremities 93 and 94, respectively. (See FIG. 6).As in the previous embodiment, the distal extremity 94 may be foldedinwardly into the interior of the balloon 92 to reduce the overallballoon length by approximately one-half. As previously described, theballoon 92 may have its overall length reduced even further byadditional inward folding. As shown in FIG. 6, the balloon 92 has asleeve 96 extending axially thereof for at least a potion of its length.The sleeve 96 surrounds the tubular member 81 and secures the balloon 92to the tubular member 81. The sleeve 96 is provided with a weakenedregion 97 extending the length thereof to permit the balloon 92 to beremoved from the tubular member 81. A tubular member 98 of the typepreviously described extends into the interior space of the balloon 92and may be connected to a suitable inflation source, such as a syringe,for example, to communicate fluid through its internal lumen into theballoon 92.

As in the previous embodiment, a removable balloon cover 101 may beutilized in connection with the apparatus 71. Alternatively, an integralballoon cover, as previously described, may also be used. The ballooncover 101 surrounds the folded balloon 92 and retains the balloon 92 inclose proximity to the tubular member 81 prior to removal of the cover101 and deployment of the balloon 92. The balloon cover 101 bas aweakened region 102 (see FIG. 6) extending the length thereof and may beprovided with a finger ring 103 to facilitate removal of the cover 101,as previously described.

A skin seal 106 of the type previously described may also be utilized inconnection with the apparatus 71. The skit seal has a conical surfacewhich is provided with a continuous helical thread 111. An axiallymovable collar 112 is mounted on the skin seal 106 and is moveable toreleasably clamp the skin seal to the scope cover 81.

Operation and use of the extraluminal balloon dissection apparatus 71 isvery similar to that of the balloon dissection apparatus 11 previouslydescribed. The principal difference in the this embodiment is that alaparoscope 72 is continuously available during the introduction of theapparatus 71 into an incision and during advancement of the apparatus 71alongside the elongate structure or vessel to be dissected free ofadjacent tissue. As before the apparatus 71 can be tunneled alongsidethe saphenous vein, either on the side of the saphenous vein adjacentthe skin, or on the side away from the skin. The balloon 92 is theninflated to dissect the vein away from adjacent tissue beyond the distalend 84 of the tubular member 81. It has been found preferable to dissectalongside the saphenous vein on the side of the leg away from the skin.By utilizing this approach, the light from the laparoscope 72 makes itpossible to visually identify the saphenous location and side branchesby forming a silhouette on the skin. This makes it possible to locatefurther necessary incisions and minimize their size.

After the balloon 92 has been disposed adjacent the saphenous vein orother elongate structure, the cover 101 is removed from the foldedballoon 92 and tubular member 81, by separation along its weakenedregion 102. Removal of the cover 101 is facilitated by finger ring 103.The balloon 92 is then inflated, and the balloon 92 unrolls and evertsin a distal direction to dissect the saphenous vein from adjacent tissuebeyond the distal end 84 of the tubular member 81. (If an integral coveris utilized in lieu of the hard cover 101, the integral cover rupturesalong its weakened region during inflation thereby releasing the balloon92). The balloon 92 can be viewed through the laparoscope 72 as itunrolls through the laparoscope 72. After the balloon 92 is completelydistended and inflated, it can be deflated as previously described andstripped off the tubular member 81 along the weakened region 97, andwithdrawn through the incision. Thereafter, the skin seal 106 may bethreaded into the incision to provide a substantially gas-tight sealtherewith if a gas-tight operating space is desired. The laparoscope 72and tubular member 81 can then be removed from the skin seal 106 and acannula having an insufflation capability can be introduced through theskin seal 106 to insufflate the dissected anatomic working spaceadjacent the vessel. Alternatively, another incision can be made and thedesired surgical procedure can be performed through the other incisionwhile viewing through the laparoscope 72 already inserted in the firstincision Thus, the balloon dissection apparatus 71 offers the advantagesobtained with the balloon dissection apparatus 11 previously described,while at the same time making it possible to view blunt dissection as itoccurs adjacent the saphenous vein or other elongate structure.

Referring now to FIGS. 7 through 9, another embodiment of a balloondissection apparatus 121 according to the present invention isillustrated. The apparatus 121 is substantially similar to the apparatus71 of the previous embodiment, the difference being that the tubularmember 81 is inserted into (rather than being disposed alongside) theelongate balloon 136. As in the previous embodiment, the tubular member81 receives a conventional laparoscope 72 and serves the dual functionof a scope cover and blunt tunneling member.

As shown in FIG. 7, the tubular member 81 is inserted inside theinverted and folded elongate balloon 136 between one of the inwardlyfolded layers of the balloon 136 and an outer, proximal balloon layer.The elongate balloon 136 may have its proximal end 137 secured to thetubular member 81 in a fluid-tight manner, such as by gluing or otherbonding techniques. Alternatively, the elongate balloon 136 may becompletely sealed, and the tubular member 81 inserted into the proximalend of the elongate balloon 136, inverting the sealed balloon 136inwardly as the tubular member 81 is advanced toward the distal mostportion of the balloon 136, as disclosed in application Ser. No.08/570,766.

In the exemplary embodiment of FIG. 7, the distal portion 139 of theballoon 136 is inverted and folded into the proximal portion 137 of theballoon 136 such that the distal half of the balloon 136 resides withinthe proximal half, as previously described. The tubular member 81 isinserted shroud the open proximal end of the balloon 136 and advancedbetween the balloon layers defining the proximal and distal halves ofthe balloon 136 until its distal extremity is adjacent the approximatemidpoint now distal, fold in the balloon 136. Because the tubular member81 and hence, the laparoscope 72, are within the interior space of theballoon 136, the balloon 136 is preferably formed from a substantiallytransparent material so that laparoscopic observation is still possible.In this case, observation occurs through the distal extremity of thetubular member 81 and the folded balloon 136. An opaque baffle 86, aspreviously described, may be utilized to minimize unwanted reflectionsof light into the laparoscope 72. Alternatively, a tubular member 81having an open distal end substantially as described in copendingapplication Ser. No. 08/570,766 may be utilized so that laparoscopicobservation is trough the open distal end of the tubular member 81.

A balloon cover 146, having a longitudinally extending and weakenedregion 147, may also be utilized in this embodiment. The balloon cover146 serves to compress the folded collapsed balloon 136 into a morecompact state and to functionally retain the balloon 136 on the tubularmember 81 during tunneling advancement of the apparatus 121. It is to benoted that an integral cover, as previously described, could be utilizedin lieu of the removable balloon cover 146 in this embodiment as well.

Operation and use of the balloon dissection apparatus 121 issubstantially similar to that of the previous embodiments. Because theballoon 136 and the distal extremity of the scope cover 81 aresubstantially transparent, observation through the laparoscope ispossible during blunt tunneling and subsequent balloon dissection. Afterthe apparatus 121 has been inserted through an incision adjacent theelongate structure to be dissected and advanced bluntly underlaparoscopic observation, if desired, to the location where dissectionis to be preformed, the balloon cover 146 is removed and the balloon 136is inflated through the tubular member 98. The balloon cover 146 isremoved by pulling the finger ring 103 proximally to cause the ballooncover 146 to separate from the tubular member 81 and balloon 136 alongits weakened region 147.

As the balloon 136 is inflated, it everts and propagates distallyfollowing a natural separation plane alongside the elongate structure ina manner similar to the balloons previously described. The balloon 136inflates around the tubular member 81 providing an anatomic workingspace adjacent the elongate structure, as shown in cross-section in FIG.9. After the elongate structure has been dissected from adjacent tissueby the balloon 136, the balloon 136 is deflated and the apparatus 121and laparoscope 72 are withdrawn through the incision, either Seriallyor together. The remainder of the surgical procedure is then completedand the incision (or incisions) closed.

Another embodiment of a balloon dissection apparatus 200 according tothe invention is shown in FIGS. 10 and 11. The apparatus 200 is providedwith a laterally extending thumb-shaped reservoir 201 which is itselfpart of the elongate balloon 203. A housing 202 having a tubular balloonsleeve 206 extending therefrom terminates the balloon 203 and mayreceive a laparoscope (not shown) if visualization is required ordesirable for the procedure contemplated. An instrument seal 204, whichmay be of the type described in copending application Ser. No.08/570,766, is mounted in the housing 202 to provide a fluid-tight sealbetween the interior of the handle 202, which is in fluid communicationwith the interior of the balloon 202, and a laparoscope. The balloonsleeve 206 is similar to the balloon sleeve described in copendingapplication Ser. No. 08/403,012, and may be formed integrally with thehousing 202 or as a separate member.

The elongate balloon 203 is substantially similar to the balloonsutilized in connection with the previous embodiments and may be invertedand folded inwardly to reduce its predeployment length in similarfashion. The proximal end of the balloon 203 is open and may beterminated in a fluid-tight manner in the housing 202, as shown, or on aouter surface of the balloon sleeve 206. The open proximal end of theballoon 203 maybe secured between the interior of the housing 202 andthe balloon sleeve 206 as described in application Ser. No. 08/403,012.The balloon 203 is preferably formed from a substantially transparentmaterial to facilitate laparoscopic observation through the balloon 203as described below.

Prior to use, the distal portion 205 of the deflated balloon 203 isinverted and folded inwardly to shorten the overall length of theballoon 203. The distal portion 205 of the inverted, folded balloon 203is pushed into the reservoir 201, as shown in FIG. 10. Additional foldsmay be provided, as necessary, to further shorten the deflated balloon203 and to make it possible to store the majority of the balloon 203 inthe reservoir 201.

The reservoir 201 provides several advantages over the previousembodiments. First, the reservoir 201 allows a more compact design inthat a long balloon may be folded and stored in the reservoir 201outside the body with only a relatively about portion of the balloon 203extending into the incision. This feature is advantageous because itallows the use of a relatively short insertion device (i.e., the balloonsleeve 206 or the distal tip of the laparoscope when the balloon sleeve206 is not provided, as shown in later embodiments of the invention, ora finger of hand) instead of the relatively long tunneling memberscontemplated in the previous embodiments. In this regard, it has beenfound desirable to utilize the balloon 203, which follows a naturaldissection plane, rather than a blunt tunneling member, which may notfollow the natural plane, to perform as much of the dissection aspossible. Second, because the majority of the balloon 203 is disposedoutside the body, the axial length of the balloon 203 is not asconstrained to the length of the tunneling member as in previousembodiments.

An inflation harness 214, also of the type previously described inSerial No. 08/570,766, may be utilized to communicate a suitableinflation medium, such as saline solution, for example, to the interiorof the balloon 203 to inflate the balloon 203. An inflation lumen 207extends from the balloon 203 and is connected to a tubular member 208,which in turn is connected to a wye fitting 209. Wye fitting 209 mayhave one port connected to a luer-type fitting 213 and another portconnected to another tubular member 211. A pinch clamp 210 is mounted onthe tubular member 211 and is clamped off dung balloon inflation andopened during deflation A male fitting 212 terminates the tubular member211 and is suitable for connecting to a hospital evacuation source whenit is desired to deflate the balloon 203.

In a preferred method of use, a laparoscope is inserted through theinstrument seal 204 and advanced through the balloon sleeve 206 untilits distal end reaches the distal end of the balloon sleeve 206 and thefolded balloon 203 which covers the distal end of the balloon sleeve206. The apparatus 200 may the be inserted into the body of a patientthrough an incision adjacent the elongate structure to be dissected.Alternatively, the apparatus 200 may be introduced through the incisioninto the body without the aid of the laparoscope if observation is notrequired or deemed necessary. Although a laparoscope is preferablyutilized with the apparatus 220, its use is optional in that the balloonsleeve 206 functions as a sepal tunneling member to facilitateadvancement of the apparatus 200 to the desired point adjacent theelongate structure.

When a laparoscope is utilized, the apparatus 200 is advanced alongsidethe elongate Structure using the laparoscope and/or balloon sleeve 206as tunneling members until a desire location for balloon dissection isreached. It is to be noted that the reservoir 201 does not generallyenter the incision and remains outside the body. When the desiredlocation is reached, the balloon 203 is inflated by connecting asuitable inflation source, such as a syringe, for example, to the luerfitting 213 and introducing the inflation medium into the interior ofthe balloon 203. As the inflation medium is progressively introduced,the balloon 203 everts outwardly propagating alongside the elongatestructure to dissect adjacent tissue away from the structure, aspreviously described. As the balloon 203 is inflated, the distal portion205 of the balloon 203 stored in the reservoir 201 is graduallywithdrawn from the reservoir by the distal propagation of the balloon203. Inflation continues until the distal portion 205 of the balloon 203is completely withdrawn from the reservoir 201 and the balloon 203 isfully distended alongside the structure. (See FIG. 11) The surgeon canobserve the progress of the dissection procedure through the laparoscopefrom inside the balloon 203 as the balloon 203 unrolls and propagatesalongside the structure.

After an operating space adjacent the vessel or structure has beencreated by dissection, the elongate balloon 203 is deflated by openingthe pinch clamp 210 and withdrawing the fluid from the balloon 203through the male fitting 212. The laparoscope and apparatus 200 may bewithdrawn from the incision and additional cannulas or otherlaparoscopic instruments, as contemplated by the particular procedurebeing performed, may be inserted through the incision into the dissectedoperating space and the procedure completed.

Turning now to FIGS. 12 and 13, another embodiment of an extraluminalballoon dissection apparatus 225 according to the invention isdisclosed. FIG. 12 illusion the apparatus 225 as it would appear priorto use with the elongate balloon 203 inverted, folded and stared withinballoon reservoir 201. FIG. 13 illustrates the apparatus 225 after theballoon 203 has been inflated and fully distended. The apparatus 225 isidentical to the previous apparatus 200 except that the balloon sleeve206 has been omitted and the inflation harness 214 has been relocatedfrom the side of the balloon 203 to the reservoir 201. In this regard,it should be noted that the inflation harness 214 in the embodiment ofFIGS. 10 and 11 could also extend from the reservoir 201.

Use of the apparatus 225 is likewise identical to use of the apparatus200, with the exception that a laparoscope (not shown) is preferablyutilized to guide the apparatus 225 into the incision and to advance theapparatus 225 to a point adjacent the elongate structure to bedissected. The surgeon may also manually insert the apparatus 225 intothe incision adjacent the elongate structure without the aid of alaparoscope.

If observation is desired, the laparoscope is inserted through the seal204 in the housing 202 and may be advanced distally into the reservoir201 following the withdrawal of the folded balloon 203 from thereservoir 201. As continued inflation causes the folded balloon 203 topropagate distally, the portion of the balloon 203 stored in thereservoir 201 is withdrawn and the laparoscope may be further advancedinside the interior space of the distended balloon 203 as desired. Theflexible apparatus 225 allows the insertion angle of the laparoscope tobe easily adjusted to parallel the structure being dissected.

In FIG. 14, an extraluminal balloon apparatus 230 has bulb-shapedballoon 222 with an elongate neck which may be utilized in place of theelongate hot dog shaped balloon 203 of the apparatus illustrated inFIGS. 10 and 11. Similarly, FIG. 15 illustrates an apparatus 235 havinga bulb-shaped balloon 222 with an elongate neck 221 in place of theelongate balloon 203 in the apparatus of FIGS. 12 and 13. Other than theshape of the balloon 222, the embodiments of the invention illustratedin FIGS. 14 and 15 are identical to their counterpart elongate balloon203 embodiments illustrated in FIGS. 10 and 11 and FIGS. 12 and 13,respectively.

The balloon 222 utilized in the FIGS. 14 and 15 embodiments has a widesurface area distal portion which may be shaped as illustrated, or inany one of the shapes illustrated in application Ser. No. 08/570,766,for example. An elongate neck 221 extends from the distal portion of theballoon 222 and may be terminated within the housing 202 or on theballoon sleeve 206 (if utilized) as previously described. The deflatedballoon 222 may be inverted inwardly, and the outer of the distalportion of the balloon 222 wrapped or folded together to compact andshorten the balloon 222. The inwardly folded and wrapped balloon 222 maythen be pushed inside the balloon reservoir 201, as in previousembodiments.

When the balloon 222 is inflated, it will evert and propagate distallyin a similar many to that of the elongate balloon 203 of the previousembodiments. When the balloon 222 is essentially fully everted, the sidemargins of the distal portion of the balloon 222 will unroll, and thedistal portion of the balloon 222 will fully expand. The balloon 222 maybe used either as a dissector or as a retractor, depending on theapplication. One application where the balloon 222 has been found tohave particular utility is in connection with an aortic bifemoral bypassprocedure, where either apparatus 230 or 235 may be inserted into thefemoral canal of the patient and then inflated to cause the balloon 222to dissect and retract the peritoneum from the pelvic floor.

FIGS. 16 and 17 illustrate a bi-directional extraluminal balloondissection apparatus 240 which is provided with two integrally formedballoon reservoirs 201, each of which function to store approximatelyone-half of the bi-directionally expanding elongate balloon 242. Theballoon 242 has a left portion 243 and a right portion 244, as shownpacked in the reservoir 201 in the deflated predeployment state in FIG.16 and in the fully expanded distended state in FIG. 17. The respectiveright 244 and left 243 halves of the elongate balloon 242 may beinverted inwardly and folded in the manner previously described. Eachrespective half of the folded elongate balloon 242 is then pushed intothe opposite reservoir 201. A balloon inflation harness 214 of the typeutilized in the previous embodiments may be utilized to inflate theballoon 242 and may be located on either one of the balloon reservoirs201 or at some other point on the balloon 242.

The method of using the apparatus 240 is substantially similar to themethods of use previously described with regard to the priorembodiments. The apparatus 240 is inserted through an incision adjacenton elongate and the balloon 242 is inflate. The right 244 and left 243halves of the balloon 242 may be deployed simultaneously orsequentially, as desired. In practice, the right 244 and left 243 halvesof the balloon 242 can be made to deploy sequentially, by manually orotherwise impeding from unfolding one of balloon halves while the otherhalf is permitted to unfold. After the first half has unfolded and fullydistended, the manual restraint may be released to deploy the otherhalf. Each half of the balloon 242 everts and propagates distally withthe folded balloon halves withdrawing from the reservoir 201 as theballoon halves propagate in the manner previously described.

A practical use of the apparatus 240 illustrated in FIGS. 16 and 17 iswhere it is desirable to avoid an anatomical structure that lies in thedesired dissection path if a single entry point were utilized, or astructure which might impede dissection. Alternatively, the apparatus240 may be utilized where it is desired to make an incisionapproximately at the midpoint of the portion of the elongate structureto be dissected and then to dissect the structure away from adjacenttissue in both axial directions. One example of a location where it maybe desirable to utilize the bi-directional balloon 242 is the knee,where anatomical structure within the knee may preclude, or makedifficult, use of an apparatus in which the dissecting balloon onlyexpands in one direction. The balloon 242 can be inserted through auincision adjacent a blocking anatomic structure, and inflated to causethe balloon halves to propagate in opposite axial directions alongsidean elongate structure, thereby avoiding the blocking structure.

FIGS. 18 and 19 illustrate a variation on the apparatus 240 illustratedin FIGS. 16 and 17. The extraluminal balloon dissection apparatus ofFIGS. 18 and 19 differs from the apparatus 240, only in that housings202 having instrument seals 204 are provided to receive a laparoscope.The housings 202 and seals 204 are as previously described and aremounted on the balloon reservoirs 201 which are open-ended in thisembodiment. The open-ended balloon reservoirs 201 my be secured withinthe housing 202 in a fluid-tight arrangement, as previously described.The addition of housing 202 to the apparatus 245 permits a laparoscope(not shown) to be inserted through the instrument seal 204 and thehousing 202 into the interior space of the balloon 242. After the device245 has been inserted through an incision in the body adjacent theelongate structure by use of a finger or other aid, the elongatebi-directional balloon 242 is inflated to dissect tissue adjacent theelongate structure, starting from the middle of the structure andthereafter propagating axially in two different directions. (See FIG.19) As the balloon 242 is inflated, a laparoscope may be insertedthrough the housing 202 having the instrument seal 204 and advancedfollowing the balloon 242 alongside the structure being dissected. Inorder to advance the laparoscope into the balloon 242, it maybenecessary to bend the housing 202 and reservoir 201 slightly to alignthe laparoscope with the axis of the everting balloon 242 as it dissectsalongside the structure.

FIG. 20 illustrates the use of a reinforcing glove or sheath 250 whichmay be utilized to reinforce the region of the balloon 203 around theballoon reservoir 201. The reenforcing sleeve 250 may also extenddistally of the reservoir 201, as shown in FIG. 20. Although the use ofa reinforcing sleeve 250 is illustrated in FIG. 20 in connection withthe extraluminal balloon dissection apparatus 200 previously describedwith reference to FIGS. 10 and 11, it should be appreciated that thereinforcing sleeve 250 could be utilized in connection with any of theembodiments having a balloon reservoir, or otherwise where it is desiredto reinforce a portion of a balloon. The reinforcing sleeve 250 may beformed of the same material as the elongate balloon 203 and mounted suchthat it surrounds the reservoir 201 and the portion of the elongateballoon 203 into which the balloon sleeve 206 extends. The reinforcingglove 250 may be formed from a flat sheet or sheets of material and mayoptionally be bonded to the reservoir 201. Alternatively, a reinforcedmonolithic structure may be used. The function of the reinforcing sleeve250 is to reinforce any weak spots on a balloon that may occur, on thereservoir 201 for example, or alternatively, to reinforce a weak spot ona balloon that may occur within the body. Such weak spots may be causedby manufacturing variations in the balloon or by issue differenceswithin the body and, without reinforcement, may be manifested in balloonaneurism behavior.

From the foregoing, it can be seen that the balloon dissection apparatusand methods disclosed herein are particularly suitable for the treatmentof elongate structures, such as vessels, using extraluminal procedures.Extraluminal balloon dissection as disclosed herein has a wide varietyof applications where it is desired to dissect alongside an elongate tocreate an anatomic working space exposing the structure. The procedurescontemplated herein are minimally invasive in that small incisions areutilized and body tissue is minimally disrupted. Because dissection isalong a naturally occurring tissue plane adjacent the elongatestructure, bleeding is minimized and the time for healing is reduced.Other patient advantages offered by extraluminal balloon dissectioninclude marked reductions in recovery time and post-surgery pain overtraditional open procedures.

Having thus described an embodiment of the invention, it will now beappreciated that the objects of the invention have been fully achieved,and it will be understood by one skilled in the art that many changes inconstruction and widely differing embodiments and applications of theinvention will suggest themselves without departing from the spirit andscope of the invention. Accordingly, the written description providedherein is purely demonstrative and is not intended to be in any senselimiting.

1. A method of harvesting a length of artery from a body comprising thefollowing steps: providing an elongate dissection cannula having aclosed distal tip; inserting said dissection cannula through an openingin the body near the length of the artery; dissecting tissue away fromthe artery with said closed distal tip; and severing the artery atproximal and distal ends of the length of artery.
 2. The method of claim1 further comprising the step of retracting the dissected tissue awayfrom the artery.
 3. The method of claim 2 wherein said step ofretracting is performed by insufflation.
 4. The method of claim 2further comprising the step of removing said dissection cannula fromsaid opening in the body prior to the step of retracting.
 5. The methodof claim 1 wherein said dissection cannula further comprises a balloon.6. The method of claim 5 further comprising the step of inflating saidballoon with the balloon inserted between the artery and surroundingtissue.
 7. The method of claim 6 wherein said balloon is an evertingballoon and inflating said balloon causes said balloon to evert andadvance along the artery.
 8. The method of claim 6 further comprisingthe step of retracting the dissected tissue away from the artery.
 9. Themethod of claim 8 wherein said step of retracting is performed byinsufflation.
 10. The method of claim 8 further comprising the step ofremoving said dissection cannula from said opening in the body prior tothe step of retracting.
 11. The method of claim 1 further comprising thestep of ligating and dividing side branches from the artery.
 12. Themethod of claim 11 further comprising the step of removing saiddissection cannula from said opening in the body prior to the step ofligating and dividing.
 13. The method of claim 12 further comprising thestep of retracting the dissected tissue away from the artery.
 14. Themethod of claim 13 wherein said step of retracting is performed byinsufflation.
 15. The method of claim 13 wherein the step of removingsaid dissection cannula from said opening in the body is performed priorto the step of retracting.
 16. The method of claim 1 further comprisingthe step of inserting at least one surgical instrument through theopening in the body to divide and ligate the artery.
 17. The method ofclaim 1 wherein the step of severing the proximal end of the length ofthe artery is performed prior to the step of inserting said dissectioncannula.